And send a message, they did. Photos from the address show a visually striking image of women all in white, a statement that’s difficult to ignore.

But it’s not the first time women have made a symbolic statement in white. Let’s delve into the history.

Tom Williams via Getty ImagesWomen leaders of the House of Representatives wore white as President Donald Trump delivered his State of the Union address on Tuesday, Feb. 5, 2019.

In the early 1900s, white became the color of choice as the Women’s Social and Political Union ― which Another Magazine notes was the leading force behind the suffrage movement ― rallied across the United Kingdom. White was initially chosen because it was “inconspicuous,” while also being somewhat feminine, the magazine points out.

Emmeline Pethick-Lawrence, honorary treasurer of the Women’s Social and Political Union, chose three main colors to represent the movement ― white (for purity), purple (for dignity) and green (for hope) ― and to help participants at a 1908 rally in London’s Hyde Park present a united front, according to History.com. In the United States, white, purple and gold were the official colors of the National Women’s Party, according to The New York Times.

Another Magazine notes that while green and purple were acceptable for small events, white was encouraged for bigger gatherings.

Heritage Images via Getty ImagesSongsheet of "The March of the Women," from 1911. The songsheet is colored in the suffrage colors: purple, white and green. This anthem was written by Ethel Smyth in 1911 and was dedicated to Emmeline Pankhurst, a leading campaigner in the suffrage movement.

Following that 1908 rally in London, which attracted tens of thousands of participants, it became clear that a sea of women wearing white outfits made quite a visual impact. As noted, white was meant to represent purity. And, according to Another Magazine, many of the women fighting for the right to vote in the early 1900s knew if they wore the color and presented themselves as pure and feminine, they would get more respect from men.

Heritage Images via Getty ImagesEmmeline Pethick Lawrence (1867-1954) and Emmeline Pankhurst (1858-1928) were two leaders of the Women's Social and Political Union, the organization founded in 1903 that spearheaded the campaign for women to vote in Britain. Here, they're photographed in 1908.

Women activists in the U.S. also wore all white as they fought for women’s rights.

Universal History Archive via Getty ImagesFrank Wheeler Mondell, representative from Wyoming, with American suffragists at the Capitol in Washington, 1914.

Over the years, many other notable women have worn white as a nod to the suffrage movement and the women’s rights movement as a whole.

For instance, in 1968, Shirley Chisholm wore white on the night she became the first black woman elected to Congress.

Bettmann via Getty ImagesShirley Chisholm gives the victory sign after winning the congressional election in Brooklyn's 12th District in 1968. She defeated civil rights leader James Farmer to become the first African American woman elected to Congress.

Geraldine Ferraro also wore white to accept the nomination for vice president at the 1984 Democratic National Convention. Ferraro was the first woman to become a vice presidential nominee for a major American political party.

Bettmann via Getty ImagesGeraldine Ferraro addresses the crowd at the Democratic National Convention in 1984.

Paul Morigi via Getty ImagesDemocratic presidential candidate Hillary Clinton acknowledges the crowd at the end on the fourth day of the Democratic National Convention at the Wells Fargo Center, July 28, 2016, in Philadelphia.

Pool via Getty ImagesFormer U.S. President Bill Clinton and First Lady Hillary Clinton arrive for the Presidential Inauguration of Donald Trump on Jan. 20, 2017, in Washington, D.C.

Later that year, some Democratic congresswomen wore white to attend the president’s first major congressional address. At the time, Frankel said the decision to wear white was meant to unite the women “against any attempts by the Trump administration to roll back the incredible progress women have made in the last century,” per NBC News.

Alex Wong via Getty ImagesMembers of Congress look on as President Trump addresses a joint session of the U.S. Congress on Feb. 28, 2017, in the House chamber of the U.S. Capitol in Washington.

Ocasio-Cortez even tweeted about her outfit choice, writing that she wore all-white “to honor the women who paved the path before me, and for all the women yet to come. From suffragettes to Shirley Chisholm, I wouldn’t be here is it wasn’t for the mothers of the movement.”

SAUL LOEB via Getty ImagesSpeaker of the House Nancy Pelosi performs a ceremonial swearing-in for Rep. Alexandria Ocasio-Cortez (D-N.Y.), and her family at the start of the 116th U.S. Congress at the U.S. Capitol in Washington, D.C., Jan. 3, 2019.

And that brings us to Tuesday’s State of the Union, where the women who chose to wear white stood together for a photo ahead of the address.

ASSOCIATED PRESSHouse Speaker Nancy Pelosi (center) is joined by other women wearing white in a group photo before the State of the Union address on Capitol Hill, Tuesday, Feb. 5, 2019 in Washington.

To some, an outfit choice may seem trivial and shallow. But if these women have showed us anything, it’s that one’s clothing sometimes speaks louder than words.

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